Owen Farrell and Leigh Halfpenny kicked four penalties apiece to leave the Six Nations clash at Twickenham level with five minutes to play.

Wales replacement Williams then produced a moment of individual brilliance to rip the ball from Courtney Lawes on halfway, kick ahead and re-gather possession, before diving over for the only try of the game.

Halfpenny added the conversion to give Wales a seven-point advantage, but the hosts came storming back – and it looked like they had crossed for a try of their own in the dying seconds.

Mike Brown ‘s pass put Strettle clear on the right flank and he surged for the corner, only to be smashed back in the tackle by Jonathan Davies and Halfpenny.

It looked as though the England wing may still have grounded the ball over the line, but after several minutes studying the footage, the television match official said there was no conclusive angle and the score was not given.

The decision meant Wales grabbed the win they deserved from a hugely-physical encounter and remained on course for the Grand Slam.

However, there were plenty of positive signs for the hosts, who played their most expansive rugby of the campaign, thanks largely to Farrell’s display at stand-off.

Upbeat England coach Stuart Lancaster said: ‘Part of developing a side is giving them experience and I think both sides will look back at the game and wonder about what they could have done differently.

‘Wales are a team who have been together a long, long time and we are a team that has been together for three weeks. We should take great credit from that.’

Wales skipper and man-of-the-match Sam Warburton was delighted with the result, but refused to speculate about his side’s Grand Slam chances.

He told the BBC: ‘We knew it was going to be our toughest game so far, knew England are a quality outfit and, flipping heck, that was one hell of a Test match. To get the Triple Crown is unbelievable.

‘We’ve got Italy now at home in two weeks and that’s a must-win game for us. We can’t really look any more than one game ahead.’